Dependence of Ice Crystal Size Distributions in High Ice Water Content Conditions on Environmental Conditions: Results from the HAIC-HIWC Cayenne Campaign
Dependence of Ice Crystal Size Distributions in High Ice Water Content Conditions on Environmental Conditions: Results from the HAIC-HIWC Cayenne Campaign
复制标题
高冰水含量条件下冰晶尺寸分布对环境条件的依赖性：HAIC-HIWC 卡宴活动的结果
DOI：
10.1175/jas-d-22-0008.1
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发表时间：
2022
影响因子：
3.1
通讯作者：
Schwarzenboeck, Alfons
中科院分区：
文献类型：
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作者：
Hu, Yachao;McFarquhar, Greg M.;Brechner, Peter;Wu, Wei;Huang, Yongjie;Korolev, Alexei;Protat, Alain;Nguyen, Cuong;Wolde, Mengistu;Schwarzenboeck, Alfons
一种新的方法，自动确定观测到的颗粒尺寸分布（PSD）的模态和每种模式的伽马函数表示，用于表征2015年法属圭亚那卡宴的高海拔冰晶和高冰水含量（HAIC-HIWC）项目期间获得的数据。利用二维立体探测器和降水成像探测器测量的最大尺寸（Dmax）> 55μm粒子的PSD，显示了伽玛参数随环境条件的变化，包括温度（T）和对流特性，如云类型、中尺度对流系统（MCS）年龄、距最近对流峰的距离和下垫面特征。观察到四种模态PSD：单峰PSD和三种类型的多模态PSD（双模态1，模态之间的断点为100 ± 20μm，双模态2，断点为1000 ± 300μm，三模态PSD，两个断点）。温度和冰水含量是影响PSD形态的最重要因素，随着温度和冰水含量的增加，PSD的多模态频率增加。在（No-λ-μ）相空间中，对不同环境条件下观测到的PSD的每一个模态定义了一个等似然解的椭球。使用椭圆体之间的重叠百分比来量化不同条件下重叠椭圆体之间的差异。在大多数情况下，椭球体的体积随IWC的增加而减小，（No-λ-μ）随IWC分布的环境条件而变化。HIWC区域主要由不规则的小冰晶和冰柱组成。各模式的参数（No-λ-μ）具有相互依赖性。
A new method that automatically determines the modality of an observed particle size distribution (PSD) and the representation of each mode as a gamma function was used to characterize data obtained during the High Altitude Ice Crystals and High Ice Water Content (HAIC-HIWC) project based out of Cayenne, French Guiana, in 2015. PSDs measured by a 2D stereo probe and a precipitation imaging probe for particles with maximum dimension (Dmax) > 55μm were used to show how the gamma parameters varied with environmental conditions, including temperature (T) and convective properties such as cloud type, mesoscale convective system (MCS) age, distance away from the nearest convective peak, and underlying surface characteristics. Four kinds of modality PSDs were observed: unimodal PSDs and three types of multimodal PSDs (Bimodal1 with breakpoints 100 ± 20μm between modes, Bimodal2 with breakpoints 1000 ± 300μm, and Trimodal PSDs with two breakpoints). TheTand ice water content (IWC) are the most important factors influencing the modality of PSDs, with the frequency of multimodal PSDs increasing with increasingTand IWC. An ellipsoid of equally plausible solutions in (No–λ–μ) phase space is defined for each mode of the observed PSDs for different environmental conditions. The percentage overlap between ellipsoids was used to quantify the differences between overlapping ellipsoids for varying conditions. The volumes of the ellipsoid decrease with increasing IWC for most cases, and (No–λ–μ) vary with environmental conditions related to distribution of IWC. HIWC regions are dominated by small irregular ice crystals and columns. The parameters (No–λ–μ) in each mode exhibit mutual dependence.